What are the best practices for committing a transaction in SQL Server where TRY CATCH is used?

Here’s the best way I have found to do this: Note the use of XACT_ABORT to make sure that the errors are caught effectively, the fact that both the BEGIN and COMMIT statements are within the TRY block, and the WHILE for @@Trancount - this should ensure nested transactions are rolled back (not always applicable) The THROW statement can also replace RAISERROR for SQL versions above 2012, to rethrow the caught exception/error. As Dan Guzman states in his comment, XACT_ABORT is useful for catching errors that the TRY/CATCH construct won't, including timeouts, runtime collation errors, etc Things To Remember While You Practice Sql Server Try Catch

• The CATCH block must immediately follow every TRY block. Including any statements between the END TRY, and BEGIN CATCH is not allowed.
  
• If there are no errors in a TRY block, the control will not enter into the CATCH block. It means the controller will execute statements after the END CATCH.
  
• If there is an error in the TRY block, it immediately exits from the Try block and enters into the Catch block.
  
• The SQL TRY CATCH will catch all the errors whose severity is higher than 10, and lower than 20.
  
• SQL allows you to use the Nested TRY blocks (TRY CATCH inside another).
  
• However, the CATCH block can not handle the compile errors like Syntax errors.